Well, the Hijri date 26 Ramadan 1231 corresponds to the Gregorian date Monday, 19 August 1816. This date lies in the ninth month of the Hijri year 1231 AH, which is Ramadan of 1231 AH. Both this Hijri and Gregorian date occur on the single day that is Monday without any doubt. The Arabic date 1231/09/26 is calculated using the Umm Al-Qura calendar and the sighting of the moon. One thing to remember is that this Arabic date may occur on different Gregorian date depending upon the region and country and obviously the moon.
If you are still not sure about the date then you can use our Arabic date converter.
The following is the conversion of the Gregorian date 19 August 1816 to its equivalent Arabic date.
The following is the conversion of the Arabic date 26 Ramadan 1231 AH to its equivalent Gregorian date.
وَقَفَّيْنَا عَلَىٰٓ ءَاثَٰرِهِم بِعِيسَى ٱبْنِ مَرْيَمَ مُصَدِّقًۭا لِّمَا بَيْنَ يَدَيْهِ مِنَ ٱلتَّوْرَىٰةِ ۖ وَءَاتَيْنَٰهُ ٱلْإِنجِيلَ فِيهِ هُدًۭى وَنُورٌۭ وَمُصَدِّقًۭا لِّمَا بَيْنَ يَدَيْهِ مِنَ ٱلتَّوْرَىٰةِ وَهُدًۭى وَمَوْعِظَةًۭ لِّلْمُتَّقِينَ
And We caused Jesus, son of Mary, to follow in their footsteps, confirming that which was (revealed) before him in the Torah, and We bestowed on him the Gospel wherein is guidance and a light, confirming that which was (revealed) before it in the Torah - a guidance and an admonition unto those who ward off (evil).
Surah Al-Maaida(5:46)